Ground anchor



Nov. 24, 1953 H. B. MCKEE 2,660,276

GROUND ANCHOR Filed Oct. 31, 1950 BY m Patented Nov. 24, 1953 UNITEDSTATES PATENT OFFICE 1 Claim.

This invention relates to a ground anchor for holding guys of poles,tents, and other structures, and has as a principal object the provisionof an anchor particularly suited for use in trailer camps for anchoringawnings, in that such structures are temporary and require, not apermanent anchor, but one which may be easily installed and withdrawn.

Although ease of intentional withdrawal is a primary object of myinvention, it is a further object thereof to provide an anchor whichwill hold firmly until it is intentionally withdrawn, and which may infact be installed in duplicate to double the holding strength of anyparticular installation.

Many of the anchors hitherto in use for similar purposes screw into theground and thereby soften and dislodge the earth through which they arescrewed, making them relatively easy to pull out. holes and then expand,which is the principle utilized in my invention, but these earlieranchors suffer the disability of having exposed screw or cam mechanismswhich become clogged with earth or corroded, and also have to be buried,requiring that the holes be filled in above them when the anchors areset and then dug out again when the anchors are lifted. It is a specificobject of my invention to provide an anchor which occupies all of thehole in which it is set, requiring no filling in and subsequent diggingout, and which has its operating mechanism, except for the actual anchorblades, contained within its body so as to be protected from corrosiveand clogging contacts.

In broad terms, my invention comprises a hollow cylinder, adapted to beplaced upright in a post-hole, and carrying axially a rotatable shaftadapted to receive a guy wire and also an operating tool such as aWrench or handle. The shaft carries a plurality of anchor-blades, hingedthereto, with their free ends guided in circumferential slots in thecylinder so that rotation of the shaft in one direction causes theblades to extend outwardly through the slots, and rotation in the otherdirection retracts the blades within the cylinder. The shaft is arrangedto be coupled at either end to the shaft of a like unit, so that two ormore units may be arranged in vertical tandem, completely filling thehole in which they are sunk, so that no filling in or digging out isrequired, the blades of all the units acting responsively to rotation ofthe shaft of the uppermost unit.

Other anchors fit into prepared In the accompanying drawing,illustrative of a preferred embodiment of my invention,

Fig. 1 is a vertical sectional view of my ground anchor, taken on theplane of section l-l of Fig. 2;

Fig. 2 is a horizontal sectional view on the plane of section 22 of Fig.1; and

Fig. 3 is a horizontal sectional view on the same plane as Fig. 2, butshowing the anchor blades in retracted position.

Having reference now to the details of the drawing, I have shown in Fig.l, a cylindrical case 5 provided with end closures 6 and. 1. Theclosures 5 and l have axial openings 8 through which extends a shaft 9.The shaft 9 is threaded at its upper end it and lower end II, and a nut12 is run upon the lower end II to serve as a support bearing for theshaft. A plate I4 is secured to the shaft 9 a little above the nut l2,and a plurality of blades I5 are pivotally secured to the plate [4 bypivot bolts It. At the level of the blades I5, the case 5 is perforatedby circumferential slots ll equal in number to the blades, each of theblades entering and being guided by a slot respective thereto. Rotationof the plate I4 by means of the shaft 9 in a counter-clockwise directionas seen in Fig. 2 will retract the blades to the position shown in Fig.3. Reversed rotation of the plate It will again extend the blades to theposition of Fig. 2.

The blades l5 extend inwardly from their pivot bolts I6, as well asoutwardly therefrom, their inward ends I9 being of such lengths that, asshown in Fig. 3, they will come into abutment with the outer ends of theblades next preceding them in the direction of rotation which causesretraction of the blades. Abutment of the blades, one against another,in this manner arrests the retractive movement, thus defining a positionof full retraction. The outer ends of the blades l5 are of such lengththat when the position of full retraction is attained, as shown in Fig.3, they will still be engaged in the slots l1 and thus will be preventedfrom yielding to pressure of the abutting blades. The extreme outer ends20 of the blades are bevelled so as to be substantially flush with theouter surface of the cylinder 5 when the blades are in fully retractedposition, and for this purpose the bevel may be curved to conform to thesurface of the cylinder. The pointed ends of the blades are thus alsosuited for cutting into the earth when the blades are extended, and thebevels 20 may be sharpened to further assist the cutting action.

The slots l I closely fit the blades l5, so as not only to guide themwithout unnecessary free motion but to prevent entry of dirt andmoisture into the cylinder 5, which except for the narrow clearance ofthe Openings 8 around the shaft 9, is otherwise sealed, and to preventrotation of the shaft 9 beyond the position in which the blades arefully extended. For this purpose the end margins of the slots I1 are notradial to the cylinder but are parallel to the chords assumed by theblades when the blades are in fully re,- tracted position. The distancebetween point llaon the inner surface of the cylinder (see Fig. 2) andllb on the outer surface of the cylinder is just sufiicient to permitthe respective blade It to extend therethrough radially to the cylinder;the blade may turn to its retracted position with very little clearance.As the upper and lower margins of the slots ll may have practicallyslide contact with the blades, it will be seen that the operatingmechanism within the cylinder is afforded nearly complete protectionagainst the ingress of dirt. The points l'ia and llb engage the sides ofthe blades at different distances from the pivot bolts 16, the points Wetoward which the plate M turns to extend the blades being slightlycloser to the pivot bolts. These points of the end margins of the slotsll will therefore bind upon the blades if an attempt is made to turn theshaft 9. in clockwise rotation as shown in Fig. 2 beyond the positiontherein shown, thus def ning the position of maximum extension of theblades and preventing retraction from resulting from an attempt toextend the blades further. Such a limiting effect is obviously desirablewhen the anchqr cylinder is inserted in the ground and blocirs all viewof the blades.

Suitable fittin s are provided for installation upon the threaded endsIt] and II of the shaft 9 for connecting thereto the guys. to beanchored, ancther anchor in tandem, and to receive an o eratin tool-Obviou y, many types of fittin s would serve the above purposes, and Ihave shown in Fig 1 only a very simple and effective assemblage A nut.2a, of ordinary reducer type hav-. ing' an external threaded portion2011, may be placed upon. the upper shaft end IE] and will receive botha wrench and a flat nut Zl. The flat nut 2( has holes Zia. which mayreceive a key wrench to turn, the shaft and may then be laced with theend of a. u not shown. An ordinary cqupling 22 will serve to. connect.the lower shaft end ll to the upper shaft end it. of a tandem ancher,the fittings. Z8. and 2i. notbeing' installed on the. upper end of thelower member of the andem...

To, install improved. anchor, a hole is first dug or bored in theground, to a. depth to, receive. as anchor units. as, may be requiredand pr ferablyo. that. the upper closure & -the upper anchor unit isjust above ground level, for

drainage, and the hole will require no filling in above the unit. Thehole is also preferably just undersize for the width of the cylinder orcylinders 5 so that the units when pushed into the hole will fit tightlytherein. The required number of units are then connected in tandem bycouplings 22, the fittings 20 and 2| are placed on the shaft of theupper unit, and the anchor units are pushed into the hole with theirblades l5 fully retracted. A one-eighth turn (approximate) on the shaftof the uppermost unit will then cause the blades of all the units toexpand into the ground, without, however, materially softening ordisledging the earth around them. No filling-in of the hole isnecessary. A one-eighth reverse turn of the uppermost shaft will retractall the blades to. permit the anchor to be raised, and no uncovering isrequired as the anchor extends to the ground surface. The stop at bothends of the turn is automatic. A guy will ordinarily be laced in thefitting 2| after the anchor is grounded and will be removed before theanchor is lifted.

Having described and illustrated a preferred form of my invention bywayof example, I wish it understood that changes and modifications fallingwithin the scope of the appended claims are to be considered asembodiments, of the spirit of my invention and included therein.

I claim:

In a ground anchor: a cylindrical case, for insertion in a preparedground hole in substantially vertical axial position, Said case havinend olosures. and having a, plurality of circumferentially extendingshort slots; a shaft axially mounted in said case and rotatablysupported by one of said closures and extending upwardly from said case;support means carried by said shaft within said case; and bladesrespective to. said slots pivotally carried by said support. means forsimultaneous and horizontal like movement, and having their outer ends.guided, in said slots for extension. and retraction therethrough whensaid shaft is. re.- tated; said slots closely fitting said blades. toprovide opposed fulcrums upon which, said blades. m y swing; said bladpivotin o said s pport means, in an Or it spaced medially between said.haft and s se; t l ast one f said lades extending inw rd y from he. pivol axis. ther f as wh n retr c ed. to but upon. n ad acen ad while th oter n of sa d blad s are stil ngaged n he slots r ec her t sa ic iabutting then arresting further retraetive. movement.

HARRY B. McKEE.

References Cited in the file of this patent FOREIGN PATENTS.

Number

